For surgical or other procedures, medical tools having end effectors manually manipulated at the end of long extensions are frequently needed. The need particularly arises in arthoscopic and endoscopic surgery. For such procedures, medical devices, such as clamps, scissors and grippers exist in which the end effectors are located at the end of a long extension and are opened and closed by means of opposing handles located at the opposite end of the extension. Typically these devices are relatively small and are used in surgical procedures where a long narrow device provides access to tissue within the body with minimal disturbance of the adjacent tissue.
Referring to FIG. 1, generally these devices 2 have an activation mechanism 4 (only partially depicted) which, attached to articulated arms 6, causes the end effectors to open and close. Also generally these articulated arms are joined together by press-fit pins 8. Pressure applied to close the end effectors may be high enough to shear the pins 8, which then can come free during the procedure, resulting serious complications to the patient.
The present invention relates to a novel dual action drive member which does not apply pressure to close the end effectors of a medical device through pins which can come free and endanger the patient.